Annex A > Chapter 27 - Concerns 1992 > Concerns > Data collected by Dr Bolsin and Dr Black
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Data collected by Dr Bolsin and Dr Black
129 In July 1992 Dr Black's daughter began a tabulation of the data which had been collected by Dr Black and Dr Bolsin. As Dr Black described it in his written evidence to the Inquiry:
`This gave us a comprehensive data set of 233 patients who underwent operations with cardiopulmonary bypass between October 1991 and July 1992 ... the handwritten tabulation contained patients' names, dates of birth, hospital numbers, dates and descriptions of operation and details of the conduct of cardiopulmonary bypass (bypass and cross-clamp times). It also contained information on the outcome in terms of death, survival and time spent in intensive care and hospital.' [163]
130 Dr Bolsin was asked about this exercise in the following exchange:
`Q. The data you collected was from the perfusionists, was it?
`A. No, this was a new data collection and it was undertaken by Andy's daughter in her summer holiday from University. We identified the patients from several sources. Andy did most of the data collection and collation, and he would give you a better opinion of it, but I can remember going to theatre logbooks to confirm operations that he and his daughter were picking up, and I think we may have got some data from the perfusionists, but there was another source and I cannot remember what it was at the moment.
`Q. So theatre logbooks, perfusionists. What was Dr Black's daughter doing? Was she looking at the records and making notes, or what?
`A. Yes, she would be extracting the data on length of time on intensive care, length of time intubated, length of time in hospital, duration of operation, length of time on bypass, duration of cross-clamp time, those kinds of detailed data.
`A. She was studying at Reading University - I cannot remember, actually. Pass.
`Q. Was she employed by the Trust to do this job?
`A. I do not know. That was an arrangement between Andy and her, I think.
`Q. Because if it was an arrangement between Andy and her, there would, on reflection, be a breach of patient confidentiality, would there not?
`A. I am not sure if patient confidentiality was breached by this data collection.
`Q. If somebody who is not an employee of the Trust, not authorised by the Trust to do so, is going through individuals' medical records in order to extract details like cross-clamp times, bypass times and so on, that must be a breach of confidentiality, must it not?
`A. I am not sure if she may not have been an employee of the University department. I do not know whether that has any bearing on what you have just said.
`Q. Does it follow that you never made any enquiries as to why a student could properly be involved in an analysis of the sort you have described?
`A. I certainly did not make any enquiries. I assumed that the probity of an employee of the University department, albeit a technician, in dealing with patient records, was reasonably bona fide.
`Q. So you assumed that she was an employee who had the status to look at the records, without enquiring?
`A. I certainly did not make any enquiries, no.' [164]
131 The information collected was, according to Dr Black:
`... transcribed from hand-written notes (excluding patients' names and hospital numbers) on a MINITAB worksheet on an Amstrad computer in the Department of Anaesthesia. Random samples from the spreadsheet were checked against the originals for transcription errors and when in 1995 the UBHT provided tables of death or survival by type of operation, the figures were checked against the UBHT figures for repair of VSD, Tetralogy of Fallot and AVSD.' [165]
`Where there was doubt about the diagnosis and operative procedure one of the paediatric cardiologists was consulted to verify the data. This was Dr Alison Hayes, who had recently been appointed to the Bristol Royal Children's Hospital.' [166]
133 Dr Black then went on in his written statement to describe the exercise in some detail:
`There were 69 different descriptive titles for the operations carried out over the period. These needed to be classified as far as possible into the categories recognised and used by the UK Paediatric Cardiac Surgical Registry. Finding a suitably qualified independent person to do this took Dr Bolsin some time. The classification was not undertaken until 1993, and was carried out by Dr Alison Hayes, a consultant paediatric cardiologist who had relatively recently been appointed in the UBHT.
`All but 39 of the 233 cases were classifiable reasonably confidently into 19 nationally recognised categories, the remainder being unclassifiable because of absent or incomplete information. I entered the classification codes into an added column in the spreadsheet using hand-written instructions about the correspondence. I compiled tables of death or survival by nationally recognised category of operation in the age groups above or below one year. (Copies of these tables were referenced in and included with my submission to the GMC.) They allowed the mortality rates in the Bristol Royal Infirmary to be compared with the corresponding national rates for 1989 and 1991, as obtained from the UK Paediatric Cardiac Surgical Register. I also tabulated the times on cardiopulmonary bypass, the cross-clamp times, days to extubation, days in ICU and days in hospital for each category of operation in Bristol. No national comparator figures are available for the period in question. (A copy of this table was referenced in and included with my GMC statement.)
`Our records showed 42 deaths in 233 cases, giving an estimated overall mortality of about 18%. The overall mortality rate presumably reflected both the cross-section of types of operation and patient that were taken on and the way in which those cases were managed. For most of the types of operation, including the "switch" operation that came into prominence later, the numbers of cases undertaken in Bristol in the audit period were too small to allow meaningful comparison with the figures in the National Registry. There were, however, 5 categories of operation in which the numbers seemed large enough to make worthwhile comparisons with the national figures.
`For atrial septal defect and Fontan repair, the mortality rates gave no cause for concern, but there did appear to be some cause for concern in the other 3 types:
`1. for repair of VSDs, there appeared to have been 6 deaths overall in 47 operations, an estimated mortality rate of 12.7% compared with a national average of 3.4% in 1991.
`2. for operations for Fallot's tetralogy, there appeared to be 8 deaths in 29 cases, an estimated overall mortality rate of 27.5% compared with the national figure of 6.8% for 1991.
`3. for operations for AVSD, there appeared to be 5 deaths in 18 operations, an estimated overall mortality rate of 27.7% compared with the national figure of 13.9% for 1991.
`Taking together the mortality figures and the supplementary table on times spent on bypass, in ICU and in hospital, it seemed to us that there had indeed been cause for concern at a time when this was not being openly admitted by the surgeons or the management of the hospital. I gave a copy of the tabulations to Dr Bolsin who gave a copy to Professor Gianni Angelini, the incoming Professor of Cardiac Surgery. I also showed the tabulations to Professor Cedric Prys-Roberts, the head of the University Department of Anaesthesia. I retained some indirect contact with subsequent events through my academic contacts with Dr Bolsin and Professor Angelini. I understood from them that the results of our audit had been presented in appropriate quarters. I was surprised that there was no apparent response or discussion, not even to dispute the accuracy of the figures. I was present at a discussion of the figures by the group of cardiac anaesthetists in 1994. I do not know how much they did or did not contribute to the decision of the group, in October 1994, not to continue anaesthetising for switch operations.' [167]
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Footnotes
[163] WIT 0326 0014 Dr Black
[165] WIT 0326 0014 - 0015 Dr Black; see Chapter 3 for an explanation of these clinical terms
[166] WIT 0080 0112 - 0114 Dr Bolsin
[167] WIT 0326 0015 - 0017 Dr Black; see Chapter 3 for an explanation of these clinical terms